System of control.



R. C. NEWHOUSE.

SYSTEM OF CONTROL.

APPLICATION mm mm: 11. 1911.

Paten D00. 12, 11916.

RAY C. NEWHOUSJE, 0F MILWAUKEE, WISCONSIN, ASSIGNOJRI, BY MESNE ASSIGNMENTS, T0 ALLIS-CHALMERS MANUFACTURING COMPANY, A CORPORATION OF DELAWARE.

SYSTEM or common menses.

To all whom it may concern:

Be it known that I, RAY C. NnwHoUsE, a citizen of the United States, residing at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Systems of Control, of which the following is a full, clear, and exact specification.

My invention relates to electrically operated skip hoists. I

It is the object of my invention to provide a skip hoist system, for hoisting stone, coal, ore, etc., which is normally completely automatic in its operation but may be manually controlled when desired. In attaining this object I have provided a system in volving a number of novel features. The movement-,- of the skips is preferably obtained by an electric motor, and the motor is controlledby the closing of the gate of the bin from. which the material to be hoisted is supplied to the skip at the bottom of the hoist. The automatic operation ofthe motor is always in the proper direction to raise the loaded skip and lower the empty skip, the motor being reversible for this purpose. The closing of the bin gate occurs when the load in the skip at the bottom of the hoist reachesa predetermined value. Although the operation is normally entirelyv automatic, the operator may at any time as sume control and obtain any desired movement of the skips within theirlimits of movement. There are also'provided a number of safety features.

The various novel features of my invention will appear .from the description and drawings, and will be particularly pointed out in the claims.

The single figure of the drawing shows diagrammatically one embodiment of my invention.

The two skips 10 and 11 operate on the usual tracks-12, these tracks. 12' being arranged so that the skips pass each. other without interference and yet each skip when at the bottom of the hoist occupies substantially the same place as does the other skip under the same circumstances. The operating cable or cables 13 extend in the usual manner around the winding drum 14, and its ends are fastened to bails 15 pivoted to the skips near their rearends. This manner of pivoting the bails 15 allowsthe autom t c tippi g of the skips as they reach Specification of Letters Patent...

Application filed June 17, 1911. Serial No. 633,798.

the top. To obtain this tipping, the rear axle of each skip is provided with additional wheels 17 which engage the auxiliary track 18 when the skip is at the top of the hoist. As a skip approaches the top, its front axle follows the curved upper end of the main track 12 while its rear axle follows the auxiliary track 18, the skip being thus automatieally dumped; the skip 11 is shown dumpmg.

The hoisting drum 14 is operated by the motor 20, preferably being directly connected thereto. This motor may be of any desired type, being shown as an induction motor of the wound rotor type. Its primary circuit is supplied from a three phase line 21, through a circuit-breaker 22 and a reversing switch 23. The circuit-breaker 22 is biased to open position, but is held in closed position by a latch-24. The latch in turn is biased to unlatching position, but is held in latching position by a solenoid25 located in a circuit which under normal conditions is always closed. The circuit of this solenoid may be called the emergency control circuit; all the others are normal control circuits. Upon the deenergization of the solenoid 25 for any reason, the circuitbreaker 22 opens. The reversing switch 23 is preferably of the oil-immersed, doublethrow, multipole type, and is biased to open position. It is movable to its two closed positions by solenoids 26 and 27 respectively. In the rotor circuit of the motor 20 are resistance sections 28, 29, 30, and 31, which may be short-circuited by switches 32, 33, 34, and 35, operated by solenoids 36, 37, 38, and 39, respectively. The solenoids 26, 27, 36, 37, 38, and 39 are controlled by a manually operated master control switch 40, an

o electrically operated nnlltipolev double-throw switch 41, a set of switches 42 to 53 inclusive, a master direction switch 54, and a main safety switch 55.

The master controller 40 has an oil and five operative positions, and normally stands in the fifth position. 7 It is not used in the normal operation of the system, but is provided to enable the operator to take control of the systemwhen he so desires.

The double-throw switch ll is movable to its two positions bypsolenoids 56 and 57, which are respectively in series with the solenoids 26 and 27 of the reversiin switch 23. It has one pole for eachof-t e sole- Guides 58 prevent thenut 58 from.

noids 36, 37, 38, and 39, and when in its two positions respectively puts such solenoids under the control of the switches 52 and 44 to 47 inclusive'or 43. and 51 to 48 inelusive.

The switches 42 to 53 inclusive are biased to their lower positions, as by gravity, but may be raised to their upper positions by a taper-ended nut 58 traveling along a threaded rod 59 driven through suitablereducing gearing from the shaftof the motor turning. The switches 42 and 53 have upper and lower closed positions, while the switches 43 to 52 inclusive are closed only when in their lower positions. The'switches 42 and 53 in their lower positions are in the circuits'of the solenoids 56. and 26, and

' 57 and 27 respectively. The switches 43 and 52 are in the circuits "of the switches 51. to 48 inclusive; and 44 to 47 inclusive, respectively. The switches 51 to 48 inclusive or the switches 44 to 47 inclusive, ac-

cording as the double-throw switch 41 is to the right or to the left, are in the respective circuits of the solenoids 36 to 39 inclusive.- The switches 42 to 53 may be spaced as desired, evenlyor unevenly; and

the position of the switches 43 and 52 in the series may often be varied. The master direction switch 54' has on its shaft a ratchet wheel 60, the number of teeth of the ratchet wheel corresponding to the number of osi-- tions of the switch 54. This number is an even number, theswitch in alternate posi-- tions closing the circuit to the switches 42 and 43, and 52 and 53, respectively; thus oppositely controlling the direction of op- 53 must be in its upper position, or a switch.

63 must beclosed; if none of these conditions exist, the switch 55 opens and deenergizesall the normal control circuits. The switch 63 just referred to is closed whenever a mechanical brake 64, cooperating with a disk 65 on the-shaft of the motor 20, is released, and. the brake 64 is released by a solenoid 66 Whenever current is being supplied to the motor 20, the solenoid 66 being connected to the motor circuit through current transformers 67.

The automatic operation of the ratchet Wheel 60"above referred to is obtained by a finger 68 hinged on the balance arm 69 of the gate 70 of the supply bin 71. The bin gate 70 is biased to closed position by an adjustable weight 72 on the balance arm 69, theclosed position of the bin gate being indicated in dot and dash lines. During the last part of the closing movement of the bin gate 70, the finger 68 strikes one of the 'teeth of the ratchet wheel 60 and moves the master direction switch 54 from one position to the next. The bin. gate 70 carries a pivoted finger 73, which is in the .path of an arm 7 4, on the top of each skip. The finger 73 is biased into the path of the arm 74 by a light spring 75 and most of the time is held there by a latch 76, which latter is connected by suitable connecting mechanism to the balance beam 77 of a scale upon which the skip at the bottom of the hoist rests andis released upon a sufficient deflection of said beam. The platform of this scale consists of two parallel plates 78 and 79, the former being mounted on the other by a nest of springs .80. On the balance beam 77 is an adjustable weight 81 for predetermi'ning the load taken by a skip. As indicated, the bin gate is in the form of a shell or shield having side pieces through which it may be rotatably mounted for such movement from open position, indicated in the drawings, as causes swinging of the shell or shield upwardly over and around and in comparatively close" contact with the outer edge of the discharge chute of the bin so as to constitute an obstruction in the path of "material discharging from the bin. The gate moves upwardl to the position indicatedin dot and daslines.

Assume that the parts are in the position shown, the arm '74 on the skip 10 having engaged'the finger 73 and opened the bin gate 70 assuch skip approached the bottom of the hoist. Immediately upon the opening of the bin ate, the stone, ore, or other material to be Twisted, beginsto run from the bin 71 into the skip 10, which may be provided'with a lip 82 to prevent any ofthe material from falling between the gate and the skip. Thecircuit-breaker 22 is closed.

The switches 23 and 41 are in their middle or, off positions. The brake 64 is applied. The-travelingnut 58 is at the extreme left hand limit ofits movement, holding the switches. 42 to 47 inclusive in their upper positions. The switches 48 to 53 inclusive are in-their lower positions. The resistance switches 32 to 35 inclusive are in their lower or open positions.

To make the system operate automatically at full speed the master controller 40 is placed in position 5, and left there while the automatic operation is to continue. The switch 42 being in its upper position and the master controller 40 being in an operative position, the solenoid 62 is energized and the main safety switch is held in its closed position. As the skip 10 fills the plate 78 of the scale platform is depressed, first compressing the springs 80, and then engaging and depressing the plate 7 9 of the scale platform and raising the weight 81. When the load in the skip 10 reaches a predetermined value, the tilting of the balance beam 77 releases the latch 7 6, and the finger 73 momentarily swings past the arm 74 to allow the weight 72 to close the bin gate 70. This shuts off the supply of material to the skip 10. As the bin gate approaches its closed position, the finger 68 strikes one of the teeth of the ratchet wheel and moves the master direction switch '54 forward to the next position beyond that which it occupies. This completes a control circuit which extends from one side of the control supply line 83, through the switch 55, the contact 84 on the switch 54, the conductor 85, the switch 53 in its lower position, the solenoids, 57- and 27, the contacts 86 and 87 on the master controller 40, and the switch 88, to the otherv side of the line 83. The resultant energization of the solenoids 57 and 27 closes the switches 41 and 23 to the left, thus putting the resistance switches 32 to 35 inclusive under the control of the switches 52 and 44 to 47 inclusive and completing the primary circuit of the motor20'for operation in one direction. The completion of this primary circuit energizes the. solenoid 66 to release the brake 64 and close the switch 63. The motor 20. now starts slowly, driving the winding drum 14 and the rod '59; thus caus ing the skip 10 to start upward, the skip 11 to start downward, and the traveling nut 58 to start to the right. The'hinged end of the finger 73, which finger has been brought back by the spring into the path of the arm 74 and is reengaged by the latch 7 6 as soon as the skip 10has started upward, allows such arm to pass without efiect as the skip 10. rises.

from its upper to its lower position; thus breaking one maintaining branch for the circuit of the operating solenoid 62 of the switch 55 and making a potential .circuit'for' the solenoids 56 and 26. :fThe circuitof' the solenoid 62, however, remains complete. at the switch 63, which is closed at this time; and the potential circuit for the solenoids 56 and 26 is open at the switch '54.- As the nut 58 continues its movement to the right,

it nextallows thejswitch 43 to drop to its .lowerorpclosed position, thus completing an As thenut 58 moves to the right, it first allows the switch 42 to, drop nut 58 to the right next causes the switch 44 i to drop. This completes a circuit which branches from the conductor 85 and extends through the switches 52, 44, and 41 to the operating solenoid 36, the circuit continuing through the master controller 40. The resultant energization of this operating solenoid 36 closes the switch 32, thus cutting out the first section, 28, of the resistance in the rotor circuit of the, motor 20. p This causes the motor to increase in speed. As the nut 58 continues its movement to the right, the switches 45,46 and 47 drop in succession, similarly completing the circuits for the solc noids 37, 38, and 39 atid causing such solenoids to close their switches 33, 34, and 35 to cut out the resistance sections 29, 30, and 31 successively. This brings the motor 20- up to full speed.- Such full. speed continuesuntilthe skip 1O approaches its upper limit of "movement and the skipll its lower limit of movement. At the same time, the traveling nut 58 approaches its right hand limit of v movement. The tapered end of the nut 58 now raises the switches 48 to 53 inclusive successively. The raising of the first four of these switches produces no effect, as these four switches are for use in starting the motor 20 in the opposite direction. The lift ing of the switch 52 breaks the circuits for the solenoids 36 to 39 inclusive, thus deenergizing said sollenoids and causing the switches 32 to '35 inclusive to open to cut all the resistance sections 28 to 31 inclusive into the rotor circuit of the motor 20 to check the speed thereof. The lifting of the switch 53 deenergizes solenoids 57 and 27, thus causing the switches 41 and 23 to move to their middle or open positions and interrupting the supply of current to the motor 20. The intcrrup'tion'of this supply of current causes the'deenergization of the solenoid 66 and the setting of the brake 64. The resultant opening of the switch 63 doesnot deenergize the solenoid 62 and cause the switch 55 to open, because the circuit of such solenoid is now maintained by the switch' 53 in its upper position. The motor 20 and the two skips now stop, .the skips 10 and 11 having now reached their upper and lower limits respectively. The skip 10 in approaching its upf per.- limit has tipped to dumping position, the wheels on its front axle having followed the curveat the upper end of the main track 12 and the auxiliary wheels on its rear axle having followed the auxiliary track 18. The material is thus dumped from the skip into, the receiving bin 89. The arm 74 of the skip 11, as the latter has approached its lower limit of movement, has engaged the'ffinger 73 .and swung the bin gate/70 to open posi- .tion, whereupon the supply bin 71, unless jempty, immediately begins to discharge material into the skip 11. When the ski 11 is filled with a prede tooth of the ratchet wheel 60, and swings it and the master direction switch 54 forward to the next position. This brings the contact 90 of said switch into "operation, and completes a circuit which extends from one side of the line. 83 through the switch 55, the contact 90 of the switch 54, the conductor 91, the switch 42 in its lower position, the solenoids 56 and 26, the contacts 86 and 87 of the master controller 40 and the switch 88 to the other side of the line 83. The resultant energization of the solenoids 56 and 26 causes the switches 41 and 23 to close to the right, thus putting the solenoids 36 to 39 inclusive under the control of the switches 43 and 51 to 48 inclusive, completing the primary circuit of the motor 20 for operation in the opposite direction from thatabove described,.and releasing the brake 64.

The motor 20 now starts in such opposite direction, raising the skip 11, lowering the skip 10, and moving the traveling nut 58 to the lefit. As this movement of the nut 58 continues, the switches 53 to 48 inclusive drop in succession, and the resistance sections 28, 29, 30 and 31 are cut out in a manner substantially the same as that already described. The action of'the switches 53 to 48 inclusive corresponds to the previous action of the switches 42 to 47 inclusive, already described. As the parts reach their Other limits of movement, the switches 47 to 42 inclusive areraised successively, the first four of these performing no function and the last two correspondingin their action to that of the switches 52 and 53 as the nut 58 approached its right hand limit, as already described. Theskip' 10, which.is now approaching the bottom, opens the bin gate 70 in the last part of its downward movement.

From this point .the cycle above described is repeated continuously as long as any material is left in the supply bin 71. Then it automatically stops;

During the last part of the travel of the ascendingskip, the movement of this skip is not in a direction parallel-to the main track 12 but, rather, in such a direction that the skip consumes less energy of thedriving .rn'otor. As the most eflicient operation of the hoisting system is secured with a fairly constant torque on' the driving motor, it is advisable to provide means for absorbing at leastsome of the energy not needed during the final tipping movement of the ascending skip. Again, considerable energy must be absorbed in order to arrest the movement of i the descending skip. Of course, the nested nomical manner.

There is provided between the rails of the track 12, near the bottom thereof, a hook 92, which'can slide in suitable guide rails lengthwise of the track 12. This hook extends upward from the track into the path of some suitable projecting part of the skip, such as one of the axles or a book 93 firmly fastened to the body of the skip. The sliding hook 92 is attached by a sturdy cable 94 to a circular sheave 95, the cable 94 extending 'over one or more pulleys 96 to a convenient location for such sheave 95. This circular sheave 95 is mounted on the same shaft or otherwise firmly connected to a spiral sheave 97, on the periphery of which is a cable 98 attached to a heavy weight 99. When either skip approaches the end of its downward movement, the hook 93 on such skip engages the sliding hook 92, and winds the cable 98 around the spiral sheave 97, thus raising the weight 99 and storing energy in it. The pulley 95 and the sheave 96 are preferably of such relative size as to afford a speed reduction between the skip and the energy-absorb ing weight 99, such an arrangement causing considerably less shock-to the apparatus at the beginning of the weight-lifting operation. This effect is further heightened by the spiral sheave 97, the lever arm through which the weight 99 acts being considerably less when the same is at its lowest point than when at its highest point, that is, equal increments of angular travel of the sheave cause unequal increments of travel of the weight, the incrementof travel of the weight being least at the beginning of its lift. In other words, the mechanical advantage of the skip on the weight is decreased as the weight moves upward. The Weight thus assists in bringing the skips'to a standstill, this action being obtained, because of the spiral sheave 97, without any violent jerks on the mechanism or any undue strains on the cables 94 and 98.- The energy stored in the lifted weight 99 is returned to the skip when the latter starts on its upward movement, thus relieving the motor 20 of some of its starting load. The rate at which this energy is returned to the skipis a gradually decreasing one, thus relieving the starting load on the motor 20 mostly at the beginning of the movement of the latter and gradmemes ually decreasing as the motor and skips gain in speed and the extra starting load diminishes. It will be apparent that the spring platform-abutment or the energy'absorbing weight may be of such dimensions and so disposed, or both of' these elements may be of such relative dimensions and so relatively disposed, that the load on the motor, while it is in operation, may be practically constant, that is, of the value required for moving the'skips during the intermediate part of their travel, atwhich part the effort of the drivingmotor is unaffected by any of the energy absorbing devices.

If at any time during the operation of the system, the operator desires to take control, he may do so by manipulatingthe master controller 40 and the master direction switch 54. If the skips are at their limits of move ment, and the traveling nut 58 is at one of its limits of movement, the motor- 20'may be started by moving the master direction switch 54 by hand forward to the next position. This produces the same efliect as the closing of the bin gate 70, and" the motor accelerates automatically as the nut 58 moves away from its extreme position. If the motor is in motion and it is desired to stop the skips, the master controller 40 is moved backward to the OE position, thus breaking the circuits for the solenoids 36, 37, 38, and 39, the solenoids 26 and 56 or 27 and 57 whichever pair .is energized, and the solenoid 62. This interrupts all the normal control circuits, and the resultant opening of the reversing switch 23 interrupts the primary circuit of the motor and causes the setting of the brake 64. If a complete stopping of the skips is not desired, the master controller 40 may be moved less than all the way to the at position, its movementback from positions 5, 4, 3, 2, and l causing successively the deenergization of the solenoid 39, the solenoid 38, the solenoid 37, the solenoid 36, and those of the solenoids 26, 27,

' 56, 57 and 62 which then happen to be energized, and thus opening the switches operated thereby. To start theskipsagain in the same direction in which they had been traveling, themaster controller 40 is moved forward step by step to any desired position, the successive positions causing successively the closing of the primary circuit and the cutting out of the resistance sections 28, 29, 30, and 31. If it is desired to start the'moto'rs in the opposite direction, the master direction switch 54 is moved forward to the next osition and then the master controller 10 is moved forward from ofl' position, the re sults being-the same asabove described save that the motor-revolves in the opposite direction. When. once started, the system will at once take, up and continue the automatic operation already described, the parts automatically stopping when they reach their limits of movement and starting again when the skip at bottom becomes. sutficiently loaded. Automatic operation of the system at less than full speed may be obtained by placing the master controller 40 in some operative position short of position 5. Should the operator move the master direction switch from one position to the next while the parts are 'in motion, he .will cause the breaking of the primary circuit of the motor 20, the setting of the brake 64:, the opening of the switch 63, and the dropping of the start and will attain a speed determined by the position to which .the master controller 40 is advanced.

The switch 88 is provided for manually stoppingthe motor and skips independently of the master controller 40. By opening the Switch 88, the bladeleaves the contacts 100 and 101 successively. On leaving the contact l00 it dee'nergizes all the resistance-controlling solenoids 36. to 39 inclusive. By leavingthe contact 101, somewhat later, it deenergizes the solenoid of the switch 23, thus causing the breaking of the primary circuit of the motor. This avoids the jar which would be given the motor if the primary circuit were broken before the resistance in the rotor circuit were cut in. The switch 88 is generally located at some convenient point at a distance from the master controller 40.

This switch may be omitted ifv desired, in

Should the parts already described get out of order or fail to work for any reason, it is possible that the motor would overwind the cable 13 on the drum 1 1. It might even break the cable. In order to take care of this a latch 103 is placed in the path of each of the bails 15 slightly beyond the normal upper limit of movement thereof. In case of over-winding, the bail l5 strikes the latch 103 and moves it in a counter-clockwise direction. This snaps open the switch 104 in the emergency control circuit, which is that of the holding solenoid 25 of the circuitbrea-ker22, thus causing the tripping of such circuit-breaker and the breaking of the circuit of the motor 20. This stops the motor. In order to prevent the skip at the to of the hoist from falling in case the ca le has been broken by the over-winding,

the latch 103 at once automatically swings back beneath the cross-bar of the bail 15. If the skip starts to drop, this latch will therefore catch the bail and prevent such dropping.

' If the cable 13 breaks while the system is in operation, both skips may fall to the bottom of the hoist. The first skip to reach the bottom would open the bin gate 70, and would probably be traveling with so much momentum that it would raise the weight 81 sufficiently to trip the latch 7 6 and allow the bin gate to close and move the switch 5& one step forward. This would usually cause deenergizationof the solenoid 62 and the opening of the switch 55, thus breaking all the normal control circuits as well as the primary circuit of the motor. In order to provide additional protection, a snap switch 105 is arranged to be tripped by the balance beam 77 of the hoist scale as'the latter is swung upward from the impact of a falling skip on the scale platform. This switch 105 is also in theemergency control circuit, or that of the solenoid 25, and its opening produces the same results as does the opening of the switch 104. The disposition'of the switch 105 relative to the weighted beam 77 is such that ordinary operation of the beam, due to the weight of a loaded skip, is not capable of causing actuation of the switch to open position. The nest of springs 80 is for the purpose of preventing the lesser impacts occurring in the ordinary operation of the system, from tripping the latch 76 and the switch 105, for absorbing the last of the momentum of a descending skip, and for giving an ascending skip a kick at starting.

Should the voltage of the main supply circuit 21 fail for any reason while the motor is in operation, the solenoid 66 is immediately deenergized. This causes the setting of the brake 64 and the opening of the switch 63. The opening of this switch 63, the traveling nut of course being somewhere else than in an extreme position, causes the deenergization of the solenoid 62 and the opening of the switch 55. This breaks all the normal control circuits as well as the primary circuit of the motor 20. Similarly, if the voltage on the control supply circuit 83 fails for any reason while the motor is in operation, the solenoid 62 is at once d e-- energized as are all the other control circuits. This causes the switch 55 to open,

i the resistance in the rotor circuit ofthe motor to be cut in, and the primary circuit of the motor to be broken bothat the re versing switch 23 and the circuit-breaker 22., In either of these cases, the system cannot be started in operation again until the switch 55 is closed; and in order to close the switch 55 the master controller must be moved back to its first position.

Any suitable protective means may be provided for protection against overloads. In case of an overload in the arrangement illustrated, a series relay 106 opens the .circuit of the solenoid 25 and thus causes the opening of the circuit-breaker 22. In some cases the circuit-breaker 22 may be dispensed with and the switches 104, 105, and 106 put in some other suitable circuit, as in the circuit of the solenoid (52.

I have described my hoisting system in what I now consider to be its preferred form. Many of the features described can be used without others, or in specifically dif-- ferent systems, and many features may readily be modified. I aim to cover all features of my invention, whether separately or in combination, which do not depart. from the spirit and scope of my invention as set forth in the following claims.

What I claim as new is:

1. A hoisting apparatus comprising a car to be hoisted, a power-operated device for hoisting it, a bin from which material to be hoisted is supplied to the car, said bin having a gate, means for causing the closing of the bin gate when the weight of the material in the car reaches a predetermined value, and means operated by the closing of the bln gatefor causing said power-operated device tohoist the car.

2. A hoisting apparatus comprising a car to be hoisted, an electric motor for hoisting it, a bin from which material to be hoisted is supplied to the car, said bin having a gate for controlling the supply of material to the car, means for causing the closing of the gate when the material in the car reaches a predetermined weight, and means operated by the closing of the bin gate for causing the motor to be connected to hoist the car. a

3. A hoisting apparatus comprising a car, a power-operated device for raising and lowering said car, a bin from which mate rial is supplied to the car when at the bottom of its travel, said bin having agate which is automatically opened when the car reaches the bottom of its travel, means for causing the closing of said gate when the weight of the material supplied to said car has reached a predetermined value, and means operated by the closing of the bin gate to cause said power-operated device to raise the car.

4. A hoisting apparatus comprising a car, a power-operated device for raising and lowering said car, a bin from which material is supplied to the car when at the bottom of its travel, said bin having a gate which is automatically opened when the car reaches the bottom of its travel, means for causing the closing of said gate when the weight of the material supplied to said car has reached a predetermined value, means ll. w l

operated by the closing of the bin gate to cause said power-operated device'to raise the car, and means for causing the poweroperated device .to stop raising the car when the latter reaches the top of its travel.

5. A hoisting apparatus'comprising a car, an electric motor for raising and lowering said car, a bin from which material is supplied to the car when at its lower limit of movement, said bin having a gate which is automatically opened-by the car as the latter approaches said lower limit of movement, means for causing the closing of said bin gate when the weight of the material in the-car reaches a predetermined value, and means operated by the closing of the bin gate for causing the completion'of the motor circuit in the proper direction to cause it to raise the car.

6. lln combination, a car which is movable between two limits of movement, a poweroperated device for moving the car between said limits of movement, a bin from which material is supplied to the car when the latter is at one limit of its movement, said bin having a gate which is opened by the car as the latter reaches said limit of move ment, means for causing the closing of the bin gate when the weight of the material supplied to said car has reached a predetermined value, and means controlled by the closing of said bin gate -for causing said power-operated device to move said car toward the other limit of its movement.

7. ln combination, a car which is movable between two limits of movement, an electric motor for moving said car between said limits of movement, a bin from which material is supplied to said car when it is at one limit of its movement, said bin having a gate which is opened by the car as it approaches said limit of movement, means for causing the closing of said bin gate when the weight the material supplied to said car i from said bin has reached a predetermined value, and means operated by the closing of the bin gate for causing current to be supplied to said motor tocause it to move the car toward the other limit of movement.

8. a skip hoist, the combination oi two skips, a power-operated device for movingsaid skips oppositely between upper and lower limits of movement, a bin from which material is supplied to the skip at the lower limit of its movement, said bin having a gate which controls the supply of material to said skip, means for causing the closing of said bin gate when the weight of the material supplied to the skip at the-bot tom has reached a predetermined value, and means operated by the closing of the bin gate for causing said power-operated device to raise the skip at the bottom and lower the ship at the top.

91 in a skip hoist, the combination oi two skips, a power-operated device for moving said skips oppositely between upper and lower limits of movement, a. bin from which material is supplied to the skip at the lower limit of its movement, said bin having a gate which controls the-supply of said material to said skip, means for causing the closing of said bin gate when the weight of the material supplied to the skip at the bottom has reached a predetermined value, means operated by the closing of the bin gate for causing said power-operated device to raise the skip at the bottom and lower theskipat the top, and means for stopping the movement of said skip by said power-operated device when the position of the skips with relation to their limits of movement has been reversed.

10. In a skip hoist, the combination of twoskips, an electric v motor for raising and lowering said skips, the simultaneous movement of the two skips being in opposite directions, a bin from which material to be hoistedvis supplied to the skip at the bottom, said bin having a gate which controls the supply of material to the skip at the bottom and is automatically opened as either skip approaches the bottom, means for causing the closing of the bin gate when'the load in the skip at the bottom reaches a predetermined value, and a switch operatedby the-closing of the bin gate and controlling the operation of said electric motor.

11. lln a skip hoist, the combination of two skips, an electric motor for raising and lowering said skips, the simultaneous movement of the two skips eing in opposite directions, a bin from which material to be hoisted is supplied to the skip at the b 0t tom, said bin having a gate which controls the supply of material to the skip at the bottom, means for causing the closing of the bin gate when the load in the skip at the bottom reaches a predetermined value, and a switch operated by the closing of the bin gate and controlling the operation of said electric motor.

12. Pin a skip hoist, the combination of two skips, an electric motor for raising and lowering said skips, the simultaneous move ment of the two skips being in opposite directions, a bin from which material to be hoisted is supplied to the skip at the bottom, said bin having a gate which controls the supply of material to the skip at the bottom and is automatically opened as either skip approaches the bottom, means for causing the closing of the bin gate when the load in the skip at the bottom reaches a predetermined value, a switch operated by the closing of the bin gate and controlling the operation of said electric motor, and means for stopping the operation of skips by the motor when the skips reach their limits of movement,

ll 1. tl

5 terial supplied to the car for" closing the bin, and means controlled by the closing of the bin for starting thecar.

14:. In combination, a movable car, a bin from which material is supplied to the car,

bin, means controlled by the Weight of material supplied to the car for closing the bin, means controlled by the closing of the bin for starting the car, and means controlled by the movement of the car for stopping the car.

'15. In combination, a movable car, a bin from which material'is supplied to the car, means operated by the car forcontrolling the bin, and means operated by the closing of the bin for controlling the car.

16. In combination, a. movable car, an electric motor forv operating it, a gate through. which material is supplied tosaid car, and means controlled by said gate for controlling said motor. Y

17 The combination of a skip, a bin from whichmaterial is supplied to the skip, said bin having a gate, and means controlled by 3 the closing of the bin gate for controlling the operation of the skip.

18. The combination of a pair of skips movable between two limits of movement,

I a bin from which. material is supplied to a skip when it is at one limit of its movement, said bin having a gate for controlling the supply of material to a skip, and means controlled by alternate closings of the gate for producing opposite operations of the 49 skips.

19. The combination of a pair of skips movable between two limits of travel, an

electric motor for operating said skips, a bin from which material is supplied to a skip when it is at one limit of its travel, and bin having a gate which controls the supply of material to a skip, means controlled by the weight of material supplied from the bin to askip for causing the clos- 50 ing of the gate when such weight has reached a predetermined. value, and means controlled by alternate closings of said gate for ,causing opposite operations of' said motor:v

"20. The combination of a pair of skips movable between two limits of travel, an electric motor for operating said skips, a bin from which material is supplied to a skip when it is-at one limit of its travel,

said bin having a gate which controls the supply of material to a skip, and means controlled by alternate closings of said gate for causing opposite operations of said motor.

21. The combination of a pair of skips,

means operated by the car for opening the an. electric motor for operating said skips, a reversing switch for said motor, a gate controlling the supply of material to said skips, and means controlled by alternate closings of said gate for causing opposite closings of said reversing switch.

, 22. In combination, a pairof skips, an electric motor for oppositely reciprocating them between two limits of movement, a

reversing switch for the motor, a gate through which material is supplied to each of said skips when it is at one limit of its movement, and means controlled by said gate for controlling said reversing switch.

'23. In combination, a pair of skips, an electric motor for oppositely reciprocating them between two limits of move1nent, a reversing switch for the motor, a gate through which material issupplied to each of said skips when it is at one limit of its movement, and means controlled by said gate for closing said reversing switch oppositely upon alternate closings of said gate.

24. In combination, a pair of skips, an electric motor for oppositely reciprocating them between two limits of movement, a reversing switch for the motor, a gate through which material is supplied to each of said skips when it'is at one limit of its movement, means controlled by said gate for closing said reversing switch oppositely upon alternate closings of said gate, .and means for causing the opening of said reversing switch when the skips reach their limits of movement.

25. In combination, a skip, an electric motor for reciprocating said skip between two limits of movement, a reversing-switch for the motor, a gate through which material is supplied to said skip when it is at one limit of its movement, means controlled by the closing of the gate for causing the closing of said reversing switch, and means for automatically accelerating said skip upon the closing of said reversing switch, and means for first automatically decelerating the skip and then causing the opening of the reversing switch as the skip approaches a limit of its movement.

26. In combination, a skip, an electric motor forreciprocating said skip between two limits of movement, a reversing switch for the'motor, a gate through which material is supplied to said skip when it is at one limit of its movement, means controlled by the closing of the gate for causing the closing of said reversing switch, and means for automatically accelerating said skip upon the closing of said reversing switch, and means for causing the opening of the reversing switch as the" skip approaches-a limit of its movement.

27. A hoisting apparatus comprising a car to be hoisted, a motor for hoisting said car, abin from which material to be hoisted .is supplied to said car, and nieanscomprising a gate controlling the discharge of material from said bin for controlling the operation of said motor.

29. In combination, a car movable between two limits of movement, ,a motor for operating said car, means for automatically controlling said motor to cause it to reciprocate said car between said limits of move- -ment, and means for manually controlling said motor to produce operatlon of sa1d car ineither direction between the same limits of movement.

30. In combination, a car movable between two limits of movement, a motor for moving said car between said limits of movement, a gate controlling a. supply of material to said car when at one limit of its -movement, means operated by the closing of erable thereby between two limits of movement, automatic means for controlling said motor to cause it to'reciprocate said device between said limits ofmovement, and means for manually controlling the car between the same limits of movement, said automatic means prevailing'over the manual means to stop the device at the limits of movement and said manual means prevailing over said automatic means to stop the device as desired between said limits of movement.

32. In a skip hoist, the combination of a skip, means for operating said skip, and means for absorbing energy from said skip during the last portion of its descending movement and transferring energy to said skip during the first portion of its ascending movement at a varying rate, said means being inoperative to absorb or give up energy during the main portion of travel of said skip and comprising a sheave having peripheral portions of different radius.

In a hoisting apparatus, a car movable between upper and lower limits of movement, a scale platform upon which the car rests when at the lower limit of its movement, said scale platform comprising two plates held apart by springs, and a balance weight for said platform.

34:. In a; hoisting apparatus, a car movplates together.

able between upper and lower limits of movement, a scale platform upon which the car rests when at the lower limit of its movement, said scale platform comprising two. plates held apart by springs, and a balance weight for said platform, said weight being so proportiened that it is not raised until the springs in the scale platform have been compressed sufficiently to bring the two 35. In combination, a car movable between predetermined limits of movement, a gate through which material is supplied to the car when at one of its limits of movement, a motor for operating. said car, a reversing switch for the motor, meansvoperated by the closing of said gate for causing the closing of said reversing-switch in the proper direction to move the car toward the. other limit of movement, and means controlled by the movement of the car for stopping such movement when such other limit of movement is reached.

36. In a hoisting apparatus, a car movable between limits, and means for controlling the operation of said car, said controlling means comprising an energy-absorbing platform upon which said car rests at one limit of its travel, and a device operable by said car when the latter isloaded to a predetermined extent, said platform being effective duringthe latter part of the movement of said car in one direction to absorb only an amount of energy less than that required to cause operation of said device and to transmit said energy to said car during the first part of its movement in an opposite direction.

37. In .combinatioma movable car, a bin from which material is supplied to said car, 105 means effective, at times, to obstruct the passage of material from said bin, and means operable to cause movement of said car from a position in which it receives material from said bin, said latter means being 110 operable only when said obstructing means substantially prevents passage of material from said bin.

38. In combination, a car movable between two limits of movement, a motor for operating said car, means controllable by said car for causing said motor to reciprocate said car between said limits of movement, and manually operable means 'for control ling said motor to produce operationof said 12( car at difierent speeds between the same limits of. movement.

39. In a skip hoist, the combination of a skip, means for operating said skip, and means for absorbing a portion of the energy of said skip during the latter portion of its descending movement and for transferring said absorbed energy-to saidfikip at a uniformly varying rate duringthamfst part of its ascending movement, said latter we means being inoperative forenergy-transfer purposes during the'main portion of travel of said skip and comprising a movable weight adapted to be lifted to absorb energy from said skip, and an operative connection between said weight and s-aid' skip effective to cause the speed of movement of said weight to be appreciably less than that of the skip and the ratio between the speeds of said skip and said weight to be variable.

40. In a hoisting apparatus, a car movable between limits, a bin for supplying material to said car, a gate for controlling the discharge of' material from said bin, means operable by said car for controlling said gate, means operable on actuation of said gate for controlling the movement of said car between its limits, and a spring platform upon which said car rests when at the lower limit of its movement, said platform being associated withsaid gate controlling means, and being effective to absorb energy during the latter part-of the descent of said car and to transmit said energy to said car during the first part of its movement in an opposite direction.

'41. In combination, a movable car, a motor for operating said car, a gate movable. downwardly to open position and through which material is supplied to said car, and means controlled by the movement of said gate to closed position for controlling said motor.

42. The combination of a skip, a bin from which material may be supplied to said skip, said bin having a gate movable downwardly to open position, and means controlled by the closing of the bin gate for controlling the operation of said skip.

43,111 combination, a movable car, a bin from which material is supplied to said car, means effective in one position to obstruct the passage of material from said bin, and means operable to'cause movement of said car from a position in which it receives ma terial from said bin, said latter means being operable in response to movement of said first mentioned means toward a position in which it obstructs passage of material from said bin.

44. In combination, a skip movable betweentwo limits of travel, a motor for-ao-- tuating said skip, a bin from which. material may be supplied to said skip, and means for controlling said motor, said motor controlling means being operable automatically in response to the Weight of material in said skip when the latter is in position to receive material from said bin and being operable independently of the Weight of material in said skip to produce operation of said skip in either direction When between said limits of travel.

45. In combination, a skip, a motor for actuating said skip, a bin from which material may be supplied to said skip, a gate for regulating the supply of material from said bin, and means for controlling said motor, said motor controlling means being operable automatically in response to the closing movement of said bin gate and being operable independently of said bin gate.

46. In a skip hoist, the combination of a skip, means for operating said skip, and means for absorbing a portion of the energy of said skip during the latter portion of its descending movement and for transferring said absorbed energy to said skip at a uniformly varying rate duringthe first part of its ascending movement, said latter means being inoperative for energy-transfer purposes during the main portion of the travel of said skip and comprising a movable weight adapted to be lifted to absorb energy from said skip, and an operative connection between said weight and said skip effective to cause the speed of movement of said weight to be appreciably less than that of the skip.

47. In combination, a skip movable between two limits of movement, a motor for reciprocating said skip between said limits of movement, means operative in response to acontrolling effect exercised by said skip when loaded to a predetermined extent for causing said motor to accelerate said skip, and means operative to cause said motor to effect the gradual deceleration and stoppage or the acceleration of said skip when the latter is in any position between said limits.

48. In combination, a car movable between limits, a motor for operating said car, means for controlling the operation of said motor to cause it to reciprocate said car between its limits of travel, and means com arising an element having a portion normally extending into the path of movement of a portion of said car and actuatable by said car when the latter reaches a predetermined point in its travel. to cause stoppage of said motor and subsequently engageable by said car to prevent uncontrolled movement of said car in an opposite direction.

49. In combination, a car movable between limits, a motor for operating said car, means operative in response to a controlling effect exercised by said car for controlling the operation of said motor to cause it to reciprocate said ear between said limits of travel, and means operative in response to the momentum of said car on uncontrolled movement thereof in one direction to prevent further operation of said motor in response to a controlling effect exercised by said car.

50. In combination, a car movable between limits, a motor for operating said car, means operative in response to controlling effects exercised by said car for controlling the operation of sriei motor to cause it to reciprocate said car between said limits of travel, and means operative in response to the momentum of said car on uncontrolled movement thereof in one direction to render said controlling means inefl'ective to accomplish its normal function of reciprocation of said car between said limits of travel.

51. In a skip hoist, the combination of a skip, means for operating said skip, and means for absorbing a portion of the energy of said skip during the latter portion of its movement in one direction and for transferring said absorbed energy to said skip at a uniformly varying rate during the first part of its movement in an opposite direction, said latter means being inoperative for I energy-transfer purposes during the main 'peripher prising an element operable by the descending skip and a second element cooperative 20 at a peripheral portion thereof with a peripheral ortion of said first element, the al portion of one of said elements being revolubleabout an axis and including parts located at different distances from said axis of revolution.

Milwaukee, Wis, June 14, 1911.'

In testimony whereof I aflix my signature, in the presence of two Witnesses.

RAY C. NEWHOUSE.

Witnesses G. B. ScHLEY, CHAs. L. BYRON. 

